[After the plate in the _Contrib. to N. Am. Ethnology_, vol. v. (Powell’s survey, 1882), showing the trephined skull brought from Peru by Squier, in the Army Med. Museum, Washington. Squier in his _Peru_, p. 457, gives another cut, with comments of Broca and others in the appendix. Cf. in the same volume a paper on “Prehistoric Trephining and Cranial Amulets,” by R. Fletcher, and a paper on “Trephining in the Neolithic Period,” in the _Journal of the Anthropological Institute_, Nov., 1887. Cf. on Peruvian skulls Rudolf Virchow, in the third volume of the _Necropolis of Ancon_; T. J. Hutchinson in the _Journal of the Anthropological Institute_, iii. 311; iv. 2; Busk and Davis in _Ibid._ iii. 86, 94; Wilson’s _Prehistoric Man_, ii. ch. 20; C. C. Blake, in _Transactions Ethnolog. Soc._, n. s., ii. There are two collections of Peruvian skulls in the Peabody Museum at Cambridge, Mass.,—one presented by Squier, the other secured by the Haasler Expedition. (Cf. _Reports_ VII. and IX. of the museum.) Wiener (_L’Empire des Incas_, p. 81) cites a long list of writers on the artificial deforming of the skull.—ED.]] The system of record by the use of _quipus_, or knots, was primarily a method of numeration and of keeping accounts. To cords of various colors smaller lines were attached in the form of fringe, on which there were knots in an almost infinite variety of combination. The _Quipu-camayoc_, or accountant, could by this means keep records under numerous heads, and preserve the accounts of the empire. The _quipus_ represented a far better system of keeping accounts than the exchequer tallies which were used in England for the same purpose as late as the early part of the present century. But the question of the extent to which historical events could be recorded by this system of knots is a difficult one. We have the direct assertions of Montesinos, Salcamayhua, the anonymous Jesuit, Blas Valera, and others, that not only narratives, but songs, were preserved by means of the _quipus_. Von Tschudi believed that by dint of the uninterrupted studies of experts during several generations, the power of expression became developed more and more, and that eventually the art of the _Quipu-camayoc_ reached a high state of perfection. It may reasonably be assumed that with some help from oral commentary, codes of laws, historical events, and even poems were preserved in the _quipus_. It was through this substitute for writing that Montesinos and the anonymous Jesuit received their lists of ancient dynasties, and Blas Valera distinctly says that the poem he has preserved was taken from _quipus_. Still it must have been rather a system of mnemonics than of complete record. Molina tells us that the events in the reigns of all the Incas, as well as early traditions, were represented by paintings on boards, in a temple near Cuzco, called _Poquen cancha_.